Lighted arrow nocks, such as disclosed in U.S. Pat. No. 8,777,786 (Bay) and U.S. Pat. No. 9,279,649 (Bay), allow an archer to be able to more easily see the arrow in flight, see the point of arrow impact, and recover the arrow after a shot. Being able to observe the arrow in flight and see the point of impact helps the archer to diagnose problems with shooting form or bow setup and make appropriate adjustments. Perhaps more importantly, a lighted arrow nock allows an archer to more easily recover the arrow.
Bow hunters can especially benefit from using an arrow with a lighted nock device. Recovering an arrow that was shot at an animal is critical in the ethical harvest of animals, and a lighted nock device allows a bow hunter to recover the arrow and animal more easily. Upon recovering the arrow, the bow hunter can diagnose many things about the shot by inspecting the arrow.
As vertical bows and crossbows (referred to collectively herein as “bows”) have gotten more powerful current lighted nock products have demonstrated an inability to handle the forces generated during launch. If a nock breaks on launch the energy stored in the bow is not absorbed (or is only partially absorbed) by the arrow, resulting in a full or partial “dry fire” event. In a dry fire event some or all of the energy stored by the bow is absorbed by the bow itself, especially the limbs and the riser. Shattered limbs and crack risers are common outcomes of a dry fire event. Dry fire events are often catastrophic for the bow.
Many existing lighted nock systems have components that transfer forces to the inside surface of the arrow shaft, causing arrow shaft fractures, such as U.S. Pat. No. 7,021,784 (DiCarlo) and U.S. Pat. No. 9,546,851 (Kim). Some lighted nock systems that rely on nock translation to activate the light also require the entire light assembly to be removed from the arrow to deactivate the light. Most of the lighted nock systems suffer from unintended activation of the light, such as during transport, which can drain the battery.